Ruminants possess the unique ability to utilize non-protein nitrogen sources to fulfill a major portion of their dietary protein requirements. These include urea and ammonium salts of organic acids such as ammonium lactate, ammonium acetate and ammonium propionate. It has been proven that ammonium salts are equivalent to soybean meal and superior to urea and nitrogen supplements when fed to feed lot cattle. See "Fermentative Conversion of Potato-Processing Wastes Into a Crude Protein Feed Supplement by Lactobacilli", Forney, L. J. et al, Vol. 18, Developments In Industrial Microbiology, Proceedings of the Thirty-Third General Meeting of the Society for Industrial Microbiology, Aug. 14-20, 1976, Jekyl Island, Ga., pages 135-143. Thus it has been suggested that potato wastes, when properly treated, may be used as a feed.
In a non-related field the present problems attendant to sewage waste disposal are well documented. The studies currently being conducted and the processes being tested to effectively handle sewage materials are innumerable. Raw primary sludge usually contains 10.sup.8 total bacteria per milliliter (including coliform and gram negative bacteria). The efficiency of secondary treatment plants is highly variable and cannot be relied upon to produce bacteriologically safe effluent and sludge. The bacterial concentration of digested sludge typically ranges from 10.sup.4 to 10.sup.8 per milliliter. The application of raw sludge to landfill is restricted as being dangerous. The percentage of digested sludge applied to the land is expected to increase as more stringent controls are imposed on ocean and fresh water dumping as well as on air pollution from incineration.
It should be noted that proper temperature, moisture and organic nutrients found in the soil and agricultural land may actually stimulate after-growth of pathogenic bacteria. Members of each group of sewage pathogens such as salmonella and shigella can survive sewage treatment and although they remain in reduced numbers after treatment they can be recovered from the receiving soil. Enteric bacteria may survive for months in the soil therefore surviving longer than the growing season for crops. Contaminated fruits and vegetables could present a health hazard if eaten raw even after a germicidal wash. Therefore although land fill for treated sewage is being encouraged the above additional problems are presented.
The above referenced article teaches that bacteria can be successfully used with waste from potato processing and that the wastes from the potato processing will support the growth of a specific bacteria to produce a feed for ruminants. However, in the described process additional growth supplements (minerals, yeast extract, trypticase and buffers) are also necessary to support the growth of the bacteria. Further the described process requires the use of carbon dioxide to stimulate the growth of the lactobacilli.
I have discovered a process wherein sewage whether raw or digested can be made suitable for use either as animal feed or as a safe and effective fertilizer for crops utilizing specific bacteria and a carbohydrate.